Questions tagged [signature]
This tag should be used for questions regarding digital signatures. A digital signature proves that the owner of a private key produced or endorsed a given message. These are used in transactions to prove that an output can be spent in a transaction.
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Where Is Signature Data Stored In Post-SegWit Transactions?
If i'm correct, i am pretty sure that signature data such as the scriptsigsize
and scriptsig is stored outside the Tx_Data of a Bitcoin transaction. But then where is it stored? Is it in the block or ...
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How is a Bitcoin transaction signed using ECDSA?
I am quite familiar with the way secp256k1 ECDSA works as well as the equations that are utilised. However, I have no idea how this ECDSA applies to signing Bitcoin (SegWit Format) and transferring it ...
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SegWit signing algorithm and its improvement
I was reading about Segregated Witness upgrade from the book Mastering Bitcoin by Andreas and there were some questions I have not figured out. I am appreciated to get some of your help!
A) There was ...
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Can the difference be determined between two nonces k1, k2, having a linear relationship if the nonce and private key are unknown, i.e., k2 - k1 = n?
My question is related to weak signature vulnerability testing where a hypothetical attacker does not know the values of the nonce or private key itself, but can determine that the nonce 'k1' is ...
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Segwit includes the input amount in the SignatureHash. What possible attack can this prevent?
Legacy transactions only include transaction components in the SignatureHash, but segwit transactions also add the amounts of inputs in the SignatureHash.
Quoting from the Mastering Bitcoin Book:
...
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What is maxsigcachesize?
-maxsigcachesize= Limit sum of signature cache and script execution cache sizes to
What is this?
What is a sigcache?
What happens if it is set low and Can it have a bad effect?
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What is the script signature and PUSHDATA operation? [duplicate]
In bitcoin transactions, there is a part of the transaction known as the scriptSig. What does this mean? Also, what is the scriptSig (PUSHDATA opcode) operation.
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How to calculate the public key, compute point P and create signature using ECDSA?
I'm quite new to the intricacies of bitcoin cryptography and ECDSA and elliptic curve cryptography has me quite stymied. I am faced with a curve with the equation: y^2 = x^3 + 7 of order N=39 with ...
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Cryptographic digital signatures
I have a doubt since the public keys are known to everyone, so someone could falsify a transaction by writing down a deposit from a public address to another public address in a new block and solving ...
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Order of Signatures in Multisig-Scheme
3 Entities (A/B/C) create a collaborative Multisig Wallet (e.g. 2-of-3).
A creates an unsigned TX and shares it with B/C. They (B/C) sign and broadcast.
Looking at the TX on the network, can A make ...
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Standard library for schnorr signature algorithm
I am trying to create a blockchain demonstration to get used to the technology. The thing is: I want to use Schnorr signatures, but I can't seem to find a library for that, and I want to make sure ...
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Does signing a message as specified in AOPP incur a fee?
Does signing a message as specified in Address Ownership Proof Protocol (AOPP) incur a fee? I think not - there is nothing written in the specification about broadcasting
anything to the Bitcoin ...
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Is it Possible to Create Signature Chains for Private Keys to Sign Transactions with? Similar to how Certificate Authorities Use Intermediate Certs?
I am wondering if it is possible to implement this flow with bitcoin private keys, similar to how certificate authorities have a root cert and an intermediate cert used to sign csr's. It would be ...
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Bitcoin transaction inquiry
if suppose a someone offers a prize for anyone that can solve a specific challenge, how will the solver make sure that he/she collects the reward? Does the solver need to send the solution directly to ...
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What is the probability of an ECDSA signature being less than 71 bytes
Since DER requires R and s values being minimally encoded signed integers, they could be less than the expected 32 bytes. What is the probability that one or both of R and s are less than 32 bytes for ...
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Why can't I modify someone else's transactions, if I have their signature data?
As I know, signature system is adding signature to end of transaction. And doesn’t hash transaction, so others can know my signature.
If I can send a message directly to the node, can I use other’s ...
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What is the relationship between r in signature and the public key
I've been reading about ECDSA in here.
Step 11 says that
you only need the ‘x‘ value (20 bytes) for the signature, and that value will be called ‘R‘
Does that say that R is the x-coordinate of the ...
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How long is SIGHASH?
I am reading these two posts 1 2, and following step by step.
I almost understand, but I still have some questions.
Before signing, input script should be removed and replaced by pre locking script. ...
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How many times and where exactly is ECDSA used in Bitcoin?
I'm currently a little confused about where exactly ECDSA is used in the transaction process... some resources seem to say it's used once, whereas others seem to say it's used three times.
Which is ...
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How to calculate R, S, and Z from raw bitcoin transaction with witness?
How can I calculate the R, S, and Z values from a raw bitcoin transaction? I can extract them with rscan.py, but that doesn't work for new transactions.
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What is signature grinding?
What is signature grinding and why does the answer to What is the size and weight of a wrapped segwit single-sig input? "highly recommend it"?
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How to forge a signature with fixed Z value
I want to forge a signature with a fixed z value, what is the formula to do that
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What is an adaptor signature?
What is an adaptor signature in Bitcoin? A simple definition with some examples that could be understood without knowing cryptography in detail
user103136
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Curious about the Math that makes Bitcoin/Blockchain work ! Any good resources to learn it?
A bit of a background about me ; Computer Engineer but during my studies i didn't dive too deep into the maths , especially the maths that makes the blockchain and cryptography work
looking for advice ...
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Meaning of "Drop the signature" comments in OP_CHECKSIG code (Bitcoin v0.1.0)
I'm doing my homework by reading the C++ code of the 0.1.0 release of Bitcoin available here. I'm interested in better understanding how to validate transaction 1 of block 170. This transaction has ...
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What is the best site/tool/way for finding the RSZ values of a bitcoin transaction? [duplicate]
The two most popular sites for doing this are down which are https://2coin.org/ and https://2xoin.com/getRSZfromRawTX/ with no indication they'll ever return to be usable.
Can anyone here link any ...
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Why is it important that nonces when signing not be related?
I understand that if nonces (usually denoted k in the signature algorithm) are related signing with the same public key that this reveals information about the private key. I would like to get a ...
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Are there possible attack/failure scenarios when no new nodes verify old signatures anymore (keeping the assumevalid defaults)?
This question came up in a recent discussion with Hasu and I was wondering if there is a good/practical reason why a newly syncing node should change the assumevalid option to 0 (verifying all the ...
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How to get bitcoin transaction nonce from transaction signature?
Subj.
Looking for a code for calculate/get bitcoin transaction nonce. Help me please.
???
Thank you.
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how target walled address is secure to save received amount?
What about if I (as a hacker) change the amount from 5 to 1 for any transaction and put signature with my (as a hacker) Private Key and mine that block again. Yes, I lose 1 coin, At the same time isn'...
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Why is signature S value is unnecessarily high not safe?
I get frequent warning when sending RawTX to PushTX message
(Non-canonical signature: S value is unnecessarily high)
Why is signature S with a large value dangerous (that is, when the first HEX ...
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Signing a transaction(Signature must be zero for failed CHECK(MULTI)SIG operation)
I try to sign raw transaction. Here is the instruction I used for it Redeeming a raw transaction step by step example required
Python code I used to sign the transaction
import hashlib
import codecs
...
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If the nodes are what keep Bitcoin decentralized, what if some big internet company spun up 60%+ majority nodes?
If the nodes are what keep Bitcoin decentralized, what if some big internet company spun up 60%+ majority nodes?
What’s stopping them from manipulating the blockchain to change transactions?
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What exactly is signed in "prev_out"?
What is signed by scriptSig? I use my private key to sign data from the unspent transaction? I sign the "prev_out" object?
I read that the signature in "prev_out" is there to ...
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Signature doesn't prove that the owner of a Private Key produced a given message
Let's assume I am a developer of Bitcoin wallet.
If I create a private key without implementing a seed phrase methodology (not using the principles of BIP32 and BIP39), is there at least the slightest ...
user125245
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How to get Y from X
Ok, so I get address generation now, and I understand that X is hashed, however for verification of a signature, we need the public point, (x,y)
How would one get Y from X?
Lets take an example, im ...
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Which elements of a P2PKH transaction are signed by default, and how is the signature used?
I'm working through the developer guide on bitcoin.org and there is a part of the section on transactions which isn't very clear. This diagram shows the elements of a transaction which are signed ...
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Transaction signing and security: Different signing approaches
I am currently studying for an exam and reviewing a past one from the CS 251: Bitcoin and Crypto Currencies course in Stanford with the following question on transaction signing. I have written my ...
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Why is adding s values in half aggregation insecure?
Jonas Nick an Tim Ruffing discussed in a presentation that summing up the s values in signature half aggregation would be insecure (without giving the reason)
They presented a secure solution which ...
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Why is full blockwide signature aggregation of schnorr signatures non-interactive?
I can only think of the MuSig paper describing how Rouge attacks are prevented by also committing to the public key of all signers. But as far as I understand the case of multisig is not the same as ...
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Why does blockwide signature aggregation prevent adaptor signatures?
In a recent video about half signatures, Jonas Nick mentions that blockwide signature aggregation interferes with adaptor signatures and offering atomic swaps (I guess via PTLCs).
I am confused about ...
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Creating Witness Signature: non-mandatory-script-verify-flag (Signature must be zero for failed CHECK(MULTI)SIG operation)
So I am trying to do my own witness signatures as described in bip143. I have code that correctly verifies the example signature, so I thought I had a hold of the basic signing and verification. I ...
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Is this a transaction?
I found an old wallet.dat but i dont know what is this. Is it a transaction that is not signed? If yes please help. I dont have a clue about cryptography. I have read and seen some tutorials but i ...
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The example signature in BIP143 doesn't validate?
In BIP143 the first example
has a witness signature and it doesn't appear to validate/be correct?! I wrote a super simple python program to demonstrate
import ecdsa
import asn1
#Importing the 3 ...
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bip143 witness formatting
in bip143 thet define a witness signature. In the first example there is a witness broken down
witness 00
02 ...
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What does bitcoin do that prevents someone from using your coins by just generating a key pair and saying "you" sent those coins?
I think I'm missing and understanding about the current process of how your wallet works and how the transactions are signed.
For example, if I'm user "A" and there exists a transaction from ...
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What is the data structure of the signature cache in Bitcoin?
There is a signature cache in Bitcoin, which is used to cache the result of signature verification to avoid extra signature verification. What data is stored in the signature cache? Is it stored in ...
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Orderly Transition Away from ECC? Or Bitcoin to zero?
Let's say asymmetric public key cryptography is wide open, and can be broken using a public key or the signature. Namely, that I can determine the private key using the information revealed in a ...
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Are high-s ECDSA signatures forbidden in segwit witnesses?
I must have looked that up five times by now, but did segwit actually forbid high-s ECDSA signatures in witnesses, esp. in standard single-sig constructions such as P2SH-P2WPKH or P2WPKH? Or are high-...
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How to prove wallet ownership? [duplicate]
Context
I would like to verify being A has access to a wallet and hence would like to ask them to pay a minimum amount to a particular wallet address owned by someone other than me, e.g. ...
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